Can one take a DtW save against powers that affect them, but don't target them directly?
The example that raised this question was Tigarius using Null Zone which encompassed Farsight and Co.
Would any unit that would be affected get DtW?
Without looking at the rulebook, i'd say they would, even if it didn't target them specifically.
You could argue as it being a kind of peripheral protection.
If the Tau Codex gives some sort of boast to DtW rolls, then that could be wavered for a more balanced result.
No boosts, same DtW as the standard with no extra Psykers. Another reason for me to run an SM Librarian with my Farsight Squad.